In 2009 the JK's got the "Hill Assist" feature. You stab the brakes and it engages the brakes for about 10 seconds before releasing them or until you begin to move. I have an '08 so don't benefit from that feature. The key that I find matches what a few others said... deep gearing and good feel for where your clutch begins to grab. As I stated before, you can slowly release the clutch to the point that you preload the drive line, once preloaded, releasing it a bit more with the brakes at the same time will act the same as releasing the brake on an auto and hitting the gas.
There is an electronic hand throttle that is offered by some aftermarket company that can be used. Not sure how well it works.